/* hci.h - Bluetooth Host Control Interface definitions */

/*
 * Copyright (c) 2015-2016 Intel Corporation
 *
 * SPDX-License-Identifier: Apache-2.0
 */
#ifndef ZEPHYR_INCLUDE_BLUETOOTH_HCI_H_
#define ZEPHYR_INCLUDE_BLUETOOTH_HCI_H_

#include <stdbool.h>
#include <stdint.h>

#include <zephyr/net_buf.h>
#include <zephyr/bluetooth/addr.h>
#include <zephyr/bluetooth/conn.h>
#include <zephyr/bluetooth/hci_types.h>

#ifdef __cplusplus
extern "C" {
#endif

/** Converts a HCI error to string.
 *
 * The error codes are described in the Bluetooth Core specification,
 * Vol 1, Part F, Section 2.
 *
 * The HCI documentation found in Vol 4, Part E,
 * describes when the different error codes are used.
 *
 * See also the defined BT_HCI_ERR_* macros.
 *
 * @return The string representation of the HCI error code.
 *         If @kconfig{CONFIG_BT_HCI_ERR_TO_STR} is not enabled,
 *         this just returns the empty string
 */
#if defined(CONFIG_BT_HCI_ERR_TO_STR)
const char *bt_hci_err_to_str(uint8_t hci_err);
#else
static inline const char *bt_hci_err_to_str(uint8_t hci_err)
{
	ARG_UNUSED(hci_err);

	return "";
}
#endif

/** Allocate a HCI command buffer.
  *
  * This function allocates a new buffer for a HCI command. It is given
  * the OpCode (encoded e.g. using the BT_OP macro) and the total length
  * of the parameters. Upon successful return the buffer is ready to have
  * the parameters encoded into it.
  *
  * @param opcode     Command OpCode.
  * @param param_len  Length of command parameters.
  *
  * @return Newly allocated buffer.
  */
struct net_buf *bt_hci_cmd_create(uint16_t opcode, uint8_t param_len);

/** Send a HCI command asynchronously.
  *
  * This function is used for sending a HCI command asynchronously. It can
  * either be called for a buffer created using bt_hci_cmd_create(), or
  * if the command has no parameters a NULL can be passed instead. The
  * sending of the command will happen asynchronously, i.e. upon successful
  * return from this function the caller only knows that it was queued
  * successfully.
  *
  * If synchronous behavior, and retrieval of the Command Complete parameters
  * is desired, the bt_hci_cmd_send_sync() API should be used instead.
  *
  * @param opcode Command OpCode.
  * @param buf    Command buffer or NULL (if no parameters).
  *
  * @return 0 on success or negative error value on failure.
  */
int bt_hci_cmd_send(uint16_t opcode, struct net_buf *buf);

/** Send a HCI command synchronously.
  *
  * This function is used for sending a HCI command synchronously. It can
  * either be called for a buffer created using bt_hci_cmd_create(), or
  * if the command has no parameters a NULL can be passed instead.
  *
  * The function will block until a Command Status or a Command Complete
  * event is returned. If either of these have a non-zero status the function
  * will return a negative error code and the response reference will not
  * be set. If the command completed successfully and a non-NULL rsp parameter
  * was given, this parameter will be set to point to a buffer containing
  * the response parameters.
  *
  * @param opcode Command OpCode.
  * @param buf    Command buffer or NULL (if no parameters).
  * @param rsp    Place to store a reference to the command response. May
  *               be NULL if the caller is not interested in the response
  *               parameters. If non-NULL is passed the caller is responsible
  *               for calling net_buf_unref() on the buffer when done parsing
  *               it.
  *
  * @return 0 on success or negative error value on failure.
  */
int bt_hci_cmd_send_sync(uint16_t opcode, struct net_buf *buf,
			 struct net_buf **rsp);

/** @brief Get connection handle for a connection.
 *
 * @param conn Connection object.
 * @param conn_handle Place to store the Connection handle.
 *
 * @return 0 on success or negative error value on failure.
 */
int bt_hci_get_conn_handle(const struct bt_conn *conn, uint16_t *conn_handle);

/** @brief Get connection given a connection handle.
 *
 * The caller gets a new reference to the connection object which must be
 * released with bt_conn_unref() once done using the object.
 *
 * @param handle The connection handle
 *
 * @returns The corresponding connection object on success.
 *          NULL if it does not exist.
 */
struct bt_conn *bt_hci_conn_lookup_handle(uint16_t handle);

/** @brief Get advertising handle for an advertising set.
 *
 * @param adv Advertising set.
 * @param adv_handle Place to store the advertising handle.
 *
 * @return 0 on success or negative error value on failure.
 */
int bt_hci_get_adv_handle(const struct bt_le_ext_adv *adv, uint8_t *adv_handle);

/** @brief Get advertising set given an advertising handle
 *
 * @param handle The advertising handle
 *
 * @returns The corresponding advertising set on success,
 *          NULL if it does not exist.
 */
struct bt_le_ext_adv *bt_hci_adv_lookup_handle(uint8_t handle);

/** @brief Get periodic advertising sync handle.
 *
 * @param sync Periodic advertising sync set.
 * @param sync_handle Place to store the periodic advertising sync handle.
 *
 * @return 0 on success or negative error value on failure.
 */
int bt_hci_get_adv_sync_handle(const struct bt_le_per_adv_sync *sync, uint16_t *sync_handle);

/** @brief Get periodic advertising sync given an periodic advertising sync handle.
 *
 * @param handle The periodic sync set handle
 *
 * @retval The corresponding periodic advertising sync set object on success,
 *         NULL if it does not exist.
 */
struct bt_le_per_adv_sync *bt_hci_per_adv_sync_lookup_handle(uint16_t handle);

/** @brief Obtain the version string given a core version number.
 *
 * The core version of a controller can be obtained by issuing
 * the HCI Read Local Version Information command.
 *
 * See also the defines prefixed with BT_HCI_VERSION_.
 *
 * @param core_version The core version.
 *
 * @return Version string corresponding to the core version number.
 */
const char *bt_hci_get_ver_str(uint8_t core_version);

/** @typedef bt_hci_vnd_evt_cb_t
  * @brief Callback type for vendor handling of HCI Vendor-Specific Events.
  *
  * A function of this type is registered with bt_hci_register_vnd_evt_cb()
  * and will be called for any HCI Vendor-Specific Event.
  *
  * @param buf Buffer containing event parameters.
  *
  * @return true if the function handles the event or false to defer the
  *         handling of this event back to the stack.
  */
typedef bool bt_hci_vnd_evt_cb_t(struct net_buf_simple *buf);

/** Register user callback for HCI Vendor-Specific Events
  *
  * @param cb Callback to be called when the stack receives a
  *           HCI Vendor-Specific Event.
  *
  * @return 0 on success or negative error value on failure.
  */
int bt_hci_register_vnd_evt_cb(bt_hci_vnd_evt_cb_t cb);

/** @brief Get Random bytes from the LE Controller.
 *
 * Send the HCI_LE_Rand to the LE Controller as many times as required to
 * fill the provided @p buffer.
 *
 * @note This function is provided as a helper to gather an arbitrary number of
 * random bytes from an LE Controller using the HCI_LE_Rand command.
 *
 * @param buffer Buffer to fill with random bytes.
 * @param len Length of the buffer in bytes.
 *
 * @return 0 on success or negative error value on failure.
 */
int bt_hci_le_rand(void *buffer, size_t len);


#ifdef __cplusplus
}
#endif

#endif /* ZEPHYR_INCLUDE_BLUETOOTH_HCI_H_ */